Electric transformer cooling means



June 2,1931. J. L. THOMPSON 1,808,617

ELECTRIC TRANSFORMER COOLING MEANS Filed 001;. 5, 1929 Fig. 1.

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Patented June 2, 1931 UNITED STATES JOHN LINDLEY THOMPSON, or aims, ENGLAND ELECTRIC TRANSFORMER COOLING MEANS Application filed October 3, 1929, Serial No. 397,022, and in Great Britain October 13, 1928.

This invention relates to the cooling of oil immersed electrical transformers, particularly transformers of small size intended to be located in chambers situated below ground level and it has for its object to provide cooling means of a simple character whereby the heat generated in the transformer and transmitted to the surrounding oil can be extracted from the oil and dissipated in an eifective manner.

For this purpose the arrangement comprises a cooling device adapted to admit only of cooling fluid being passed through it and to present a large heat transferring surface to such fluid, and characterized in that it is secured to the outside of the transformer tank over an opening therein, external heat conducting projections being provided arranged to extend through the said opening into the oil in the tank so that heat will be conducted directly from the oil by the projections to the cooling device and thence to the cooling fluid flowingytherethrough.

The projections or fins may advanta geously be composed of material of high thermal conductivity, for instance copper or aluminium, and the cooling device through which the cooling fluid flows may also be of similar material.

In the accompanying illustrative drawings Figs. 1 and 2 are elevations at right angles to one another showing a transformer tank provided with cooling devices according to this invention.

Fig. 3 is a broken front view, showing to a larger scale than Figs. 1 and 2, one of the cooling devices with its cover removed. Figs. 4 and 5 are respectively sections on the lines IV-IV' and VV of Fig. 3 with the cover of the cooling device in position.

Referring to the construction shown in the drawings, 1 is a transformer tank provided near its upper end portion with oppositely arranged openings one on the high tension side 1 and one on the low tension side 1 of the tank. Each cooling device comprises a casting 2 of high thermal conductivity material, such as hereinbefore 5O mentioned, adapted to be secured in a liquid- .tend into the oil within the tank.

tight manner over one of the openings in the tank 1, as by bolting'flanges l thereto. The casting is provided externally on the side adjacent to the tank, with vertically arranged projecting fins 3'adapted to ex- Internally the casting is provided with a number of'outwardly extending ribs or divisions l, preferably arranged horizontally, adapted to form between them and the walls of the casting and a removable cover plate- ,5, a zig-zag or tortuous passage 6 through which cooling water can be caused to How. The

two ends ofthe passages 6 extend to the opposite ends of the casting 2, terminating near the top and bottom thereof at 2" and 2 respectively where they are adapted to be connected to pipes 7, 7*, 7 for the inlet and outlet. cooling water. The cooling water may conveniently be caused to circulate through the cooling devices in series (Fig. 2), the upper end of the tortuous water passage 6 in one cooling device being, for instance, connected to the lower end of the water 'passage in the other cooling device, as by thepipe 7, the other ends of the two passages being connected by the pipes"? and 7 to the circulating water supply system.

What Iclaim is 1. In combination, a transformer oil tank havingan opening in itswall, a cooling-dd, vice adapted 'to be secured to the outside 7 of the tank over the opening therein, heat conducting means provided externally upon 7 thecooling device and extending through 85 the opening into the tank,- and means whereby a cooling fluid is caused to flow through the device, substantially as described.

2. A transformer cooling tank having a vertical wall provided with an opening near the top, a cooling device comprising a plate member adapted to be secured to the outside of the tank over the opening aforesaid, such plate member having at one side a number of vertically arranged .heat absorbing fins extending through the openinginto the tank and at the other side a passage through which cooling fluid can be caused to flow.

3. A transformer cooling tank according to claim 2, in which the passage for the manner to a tank around an opening'therecooling fluid istortuous, being formed by a number of inter-spaced horizontal ribs. 7

4. A cooling device for use with a transformer. oil tank, said cooling device comprising a plate member adapted to be secured at its marginal portion in a fluid tight manner to the outer side of a transformer tank over an opening therein, said plate member having at'one side, thereof, Within said marginal portion, aplurality of. h

vertically arranged heat absorbing fins extending laterally beyond the plane of said marginal portion and adapted to extend through said'opening, and atrathe opposite side a tortuous passage through which cool ing fluid can be caused to flow.

5. For use with a transformer oil tank, a cooling device comprising a plate member adapted at its marginal portion to be -se cured in a fluid-tight manner to a transformer tank around an opening therein, and

having at one side a plurality of-vertically arranged heat absorbing fins and at the other side a plurality of inter-spaced ribs, said fins extending laterally beyond'the marginal portion of said plate member, a cover adapted to engage said ribs,'means for removably securing the cover to'the plate member, the ribs forming with the plate member and cover, a zig-zag passage, and V means whereby a cooling fluid can be supplied to and ledfrom such passage.

6. A cooling device for use with a transformer'oil tank, said cooling device comprising a metal casting adapted to be secured around its marginal portion in a fluid-tight in, and having integral therewith, and on one side thereof, a plurality of vertically arranged fins adapted to extend into said tank throughthe opening therein and, on y the other side, and integral therewith, a plurality of outwardly extending i horizontally arranged ribs, and a cover removably secured to said castingand adapted to engage said ribs, said ribs forming between them and the walls of said casting and said cover, a tortuous passage throughwhich cooling fluid can be caused to flow, the ends of saidpassage terminating at thejopposite ends of said casting in inlet and outlet openings. Y 1 e Signed at London, England, this 20th day of September, 1929. V r r JOHN LINDLEY THOMPSON. 

